This invention relates to the suppression of interfering signals either intentional or non-intentional and in particular to the adaptive suppression of narrow band interference using charge coupled devices. It is applicable to spread spectrum communications, radar, navigation and identification equipment.
The filtering of interference in prior art systems has been accomplished by: (1) fixed filters where the signal interference is known a priori; and, (2) adaptive filters where a single reference signal which is similar to the expected interference is known a priori. Neither technique is effective when the requirement is to suppress unknown or changing interfering signals. Systems which can economically perform a real time spectral analysis of the input signal, identify the interfering signal or signals and remove the interfering signals have not previously been practical. There currently exists, therefore, the need for a simple, practical, inexpensive circuit that is capable of adaptively suppressing interference that is not known a priori. The present invention is directed toward satisfying that need.